As shown in FIG. 10, vehicles typically include a roof drip molding disposed between the vehicle body and the door frame. In the past, this roof drip molding has been manufactured so as to possess a constant cross-section. Recently, in order to improve its design and appearance, the roof drip molding has been manufactured to possess a gradually changing cross-section along a portion of its length. For example, Japanese Patent Publication No. 5-62088 discloses a molding having a gradually changing cross-section and made of a plurality of parts. As seen in FIG. 11(a), the molding includes a main body 102, a garnish or ornamental portion 104, and a retainer 106 which is adapted to provide water sealing characteristics. The main body 102, which possesses a constant cross-section along its length, is formed by rolling a piece of metal, extruding a plastic layer onto the metal piece and then subjecting the main body to a bending operation to bend the front portion 102' relative to the center portion 102" of the main body. A portion of the metal in the main body 102 is exposed to form a shiny part of the molding while the portion of the metal that is covered by the plastic layer forms a non-shiny part of the molding.
The garnish or ornamental portion 104 is formed by stamping a metal piece and then injection molding a plastic layer onto the metal piece. A portion of the metal of the ornamental portion 104 is exposed to form a shiny part that aligns with the shiny part on the main body 102 after assembly, and the remaining portion of the metal piece that is covered with the plastic forms a non-shiny part of the ornamental portion 104. The non-shiny part of the garnish portion 104 possesses a gradually changing cross-section.
The retainer 106 is formed by rolling a piece of metal and then subjecting the metal piece to a bending operation. The garnish 104 and the retainer 106 are then assembled to one another by welding to form a rear portion of the main body. The resulting rear portion of the main body is then assembled with the main body 102 to form the molding. The molding thus possess a front portion and center portion of constant cross-section or width, and a rear portion (formed by the garnish and retainer) having a changing cross-section or width.
This construction of the molding and method of manufacturing the molding suffers from a variety of drawbacks and disadvantages. In one respect, several different parts must be formed to produce the ultimate molding. This method also requires a variety of different process steps, thus increasing the cost and time associated with manufacturing the molding. Further, when the rear portion of the main body is assembled with the remainder of the main body, a seam is formed between the two parts. This seam can have a negative influence on the appearance of the molding and can adversely affect the water sealing capabilities of the molding.
Another known construction of a roof drip molding is illustrated in FIG. 11(b) and includes a main body 110, a garnish or ornamentation portion 112 and a retainer 114. The main body 110 includes a front portion 116, a center portion 118 and a rear portion 120. The main body 110 is formed by rolling a strip of metal and applying a plastic layer along the length of the metal strip through extrusion. The width of the plastic layer is constant throughout the length of the main body and a portion of the metal strip is exposed to provide a shiny part on the main body 110. A portion of the plastic layer in the area of the rear portion of the main body is then removed through appropriate operations and the rear portion 120 of the main body 110 is then bent to produce the main body seen in FIG. 11(b).
The garnish or ornamental portion 112 is formed by injection molding and possesses a changing cross-section or width. The retainer 114 is formed by rolling a piece of metal and subjecting it to a bending operation. The garnish 112 and the retainer 114 are then assembled together, with the resulting piece being welded to the main body 110.
This construction of the molding suffers from drawbacks and disadvantages similar to those discussed above. The numerous parts and operations needed to manufacture the molding significantly increases the cost associated with the molding. Further, the seam that is created by the assembly of the parts can adversely affect the water sealing capabilities of the molding.